(14-17) This Messianic kingdom cannot have anything to do with law; for if it had, faith and the promise would cease to have any office. Faith and law cannot co-exist. They are the opposites of each other. The proper effect of law is punishment; for law only exposes sin. Faith, on the other hand, is the real key to the inheritance. It sets in motion grace; and grace, unlike law, excludes no one. It is open alike to the legal and to the spiritual descendants of Abraham; in other words (as the Scripture itself testifies), to all mankind, as the representative of whom Abraham stands before God.
(14) Is made void.--Literally, emptied of its meaning, becomes an empty name, and the promise is rendered nugatory. There is nothing left for either to do, if the votaries of law, simply as such, are to be the inheritors of the Messianic kingdom.
4:13-22 The promise was made to Abraham long before the law. It points at Christ, and it refers to the promise, Ge 12:3. In Thee shall all families of the earth be blessed. The law worketh wrath, by showing that every transgressor is exposed to the Divine displeasure. As God intended to give men a title to the promised blessings, so he appointed it to be by faith, that it might be wholly of grace, to make it sure to all who were of the like precious faith with Abraham, whether Jews or Gentiles, in all ages. The justification and salvation of sinners, the taking to himself the Gentiles who had not been a people, were a gracious calling of things which are not, as though they were; and this giving a being to things that were not, proves the almighty power of God. The nature and power of Abraham's faith are shown. He believed God's testimony, and looked for the performance of his promise, firmly hoping when the case seemed hopeless. It is weakness of faith, that makes a man lie poring on the difficulties in the way of a promise. Abraham took it not for a point that would admit of argument or debate. Unbelief is at the bottom of all our staggerings at God's promises. The strength of faith appeared in its victory over fears. God honours faith; and great faith honours God. It was imputed to him for righteousness. Faith is a grace that of all others gives glory to God. Faith clearly is the instrument by which we receive the righteousness of God, the redemption which is by Christ; and that which is the instrument whereby we take or receive it, cannot be the thing itself, nor can it be the gift thereby taken and received. Abraham's faith did not justify him by its own merit or value, but as giving him a part in Christ.
For if they which are of the law be heirs,.... That is, if the Jews who are under the law, and are seeking for righteousness and life by the works of it, should, on the account of their obedience to it, be heirs of the grace of life and of glory,
faith is made void; for if the right to the inheritance is by the works of the law, there is no room for faith; that can be of no use or service;
and the promise made of none effect: if salvation is by works, it is to no purpose for God to promise, or men to believe; for the thing promised depends not upon God's promise, but upon man's obedience to the law; and if that is not perfectly observed, as it cannot possibly be, then the promise of God stands for nothing, and is in course made void. The apostle here argues from the absurdities which follow upon the doctrine of justification by works, as he does from the different effects of the law, in the following verse.
